左精氨酸对体外循环中肺的保护作用

Protective effects of L-arginine against lung injury during cardiopulmonary bypass

研究左精氨酸（L-Arg）对兔体外循环（CPB）中肺的保护作用并探讨其机制．方法：采用兔CPB模型，给予L-Arg，测定肺组织的丙二醛（MDA），髓过氧化物酶（MPO），磷脂酶A2（PLA2），一氧化氮（NO）含量及肺组织的湿干重量之比．结果：CPB＋L-Arg组肺组织MDA含量（61．2±9．5）mmol／g明显低于CPB组（139．4±17．0）mmol／g，P＜0．01；MPO含量（5．9±0．9）IU／g明显低于CPB组（9．4±0．6）IU／g，P＜0．01；PLA2含量（8．8±1．0）IU与CPB组（12．2±3．0）IU相比差异显著（P＜0．01）；而NO含量（18．1±2．5）mmol／g明显高于CPB组（8．4±3．8）mmol／g，P＜0．01；湿干比值CPB＋L-Arg组（5．3±1．2）明显低于CPB组（8．5±2．1），P＜0．05．结论：动物实验提示CPB期间存在肺缺血／再灌注损伤，给予L-Arg可减轻肺损伤，具有保护作用．

Aim: To study the protective effects and mechanism of giving L-arginine (L-Arg) against lung injury during cardiopulmonary bypass (CPB) in rabbit. Methods:CPBmodels were set up with living rabbits by giving L-Arg.MDA, MPO, PLA, and NO contents in lung tissue were determined. Ratio of wet lung tissue to dry one was tested.Results: MDA contents of lung tissues in CPB + L-Arggroup (61. 2 ±9. 5 ) mmol/g were significantly lower thanthat in CPB group (139. 4±17. 0) mmol/g, P<0.001; MPOcontent (5. 9± 0. 9 ) U/g was significantly lower incomparison with CPB group (9. 4± 0. 6) U/g, P< 0. 01;PLA, content (8. 8± 1. 0) U was lower than that in CPBgroup (12. 2±3. 0) U, P M 0. 01; NO contents in CPBgroup (8. 4±3. 8) mmol/g were lower than that in Shamgroup (20. 9±1. 7) mmol/g, P<0. 01; and in CPB+L-Arggroup (18. 1± 2. 5) mmol/g they were higher than that inCPB group (8. 4±3. 8) mmol/g, P<0. 01; Ratio of wet /dry lung tissue in CPB+L-Arg group (5. 3±1. 2) was lower than that in CPB group (8. 5± 2. 1 ), P<0. 05. Conclusion: There is ischemic and reperfusion injury during CPBand there is protective effects after giving L-Arg, the NOprecursor.